Control pedals are typically provided in a motor vehicle, such as an automobile, which are foot operated by the driver. Separate control pedals are provided for operating brakes and an engine throttle. When the motor vehicle has a manual transmission, a third control pedal is provided for operating a transmission clutch. A front seat of the motor vehicle is typically mounted on tracks so that the seat is forwardly and rearwardly adjustable along the tracks to a plurality of positions so that the driver can adjust the front seat to the most advantageous position for working the control pedals.
This adjustment method of moving the front seat along the tracks generally fills the need to accommodate drivers of various size, but it raises several concerns. First, this adjustment method still may not accommodate all drivers due to very wide differences in anatomical dimensions of drivers. Second, the necessary position of the seat may be uncomfortable for some drivers. Therefore, it is desirable to have an additional or alternate adjustment method to accommodate drivers of various size.
Many proposals have been made to selectively adjust the position of the control pedals relative to the steering wheel and the front seat in addition to adjusting the front seat in order to accommodate drivers of various size. These adjustable control pedals can actuate either a cable which is connected to an engine throttle, for example, or an electronic throttle control (ETC) where an electric signal is sent to the engine throttle which is proportional to the positioning of the pedal. Such “drive-by-wire” ETC pedals were adapted from fly-by-wire” aircraft pedals, and the ETC can be, for example, either a dual slope potentiometer where the electric signal is proportional to rotation of the pedal, or a linear variable displacement transducer (LVDT) where the electric signal is proportional to linear displacement of the pedal or a carrier operatively connected to the pedal. See, for example, U.S. Pat. No. 5,056,742 to Sakurai showing adjustable pedals which control brakes and rudders of a motor vehicle such as an aircraft. A mounting frame or carrier is mounted in a base frame or support structure so that the carrier can be adjusted forward or rearward by operation of a screw device or drive assembly. Pedals are pivotally connected directly to the multi-part carrier for pivotal movement relative to the carrier and are moved to various adjusted positions with the forward/rearward movement of the carrier relative to the support structure. Transducers or generator means are mounted on the carrier and move with the carrier to the various adjusted positions. These transducers have outputs responsive to the pivotal movement of the pedals relative to the carrier which vary in magnitude in proportion to the extent of movement of the pedals relative to the carrier. It is readily apparent to those skilled in the art of adjustable control pedals that the pedals connected to the carrier can have many different forms depending on the requirements of the particular motor vehicle such as, for example, in automobiles the pedal is typically in the form of a pedal arm extending from a pivot connection to a lower end having a pad.
U.S. Pat. Nos. 5,632,183, 5,697,260, 5,722,302, 5,819,593, 5,937,707, and 5,964,125, the disclosures of which are expressly incorporated herein in their entirety by reference, each disclose an example of an adjustable control pedal assembly. This control pedal assembly includes a hollow guide tube, a rotatable screw shaft coaxially extending within the guide tube, a nut in threaded engagement with the screw shaft and slidable within the guide tube, and a control pedal rigidly connected to the nut. The control pedal is moved forward and rearward when an electric motor rotates the screw shaft to translate the nut along the screw shaft within the guide tube. While this control pedal assembly may adequately adjust the position of the control pedal to accommodate drivers of various size, this control pedal assembly is relatively complex and expensive to produce. The relatively high cost is particularly due to the quantity of high-precision machined parts such as, for example, the guide tube and due to the quantity of welded joints.
U.S. Pat. Nos. 3,643,525 and 3,643,524, the disclosures of which are expressly incorporated herein in their entirety by reference, each disclose an example of an adjustable control pedal assembly which is much less expensive to produce. This control pedal assembly includes an upper arm having a single horizontal slot, a rotatable screw shaft attached to the upper arm and extending along the slot, a nut in threaded engagement with the screw shaft and having a pin slidable within the slot, and a control pedal rigidly connected to the nut. The control pedal is moved forward and rearward when an electric motor rotates the screw shaft to translate the nut along the screw shaft. While this control pedal assembly may adequately adjust the position of the control pedal to accommodate drivers of various size and is relatively inexpensive to produce, this control pedal is relatively unstable and can have a relatively large amount of lash. That is, components of the control pedal are subject to vibration during regular operation of the motor vehicle causing the components to rub or strike together causing undesirable noise.
While these adjustable pedal systems may adequately adjust the position of control pedals, these systems often do not know the exact location of the control pedal and/or can cause injury or damage when the control pedals engage an obstruction. Accordingly, there is a need in the art for an adjustable pedal assembly which selectively adjusts the position of the control pedal to accommodate drivers of various size, is relatively simple and inexpensive to produce, is able reset in order to identify the exact position of the control pedal, is able to detect when an obstruction is engaged during movement of the control pedal, and/or is highly reliable to operate.